Mix the mayonnaise, dill relish, and diced chives to make the tarter sauce. Squeeze lemon juice into the sauce and season with salt and pepper, to taste.
Preheat Blackstone griddle to medium heat. Place a deep cast iron skillet on griddle top, filling with oil for deep frying the fish.
Cut Halibut filets into strips, sized as desired.
Put the flour into a bowl. Add beer and mix, adding more as needed to get the consistency of a thin pancake batter. Season with salt and pepper and mix well. Please the Halibut filets in the batter, flipping around to ensure they are fully coated.
Once the oil is around 350-375 degrees, carefully add each Halibut filet to the oil.
When fish are nicely browned, remove from the oil and let them cool down for a minute or two on a paper towel.
